The invention relates to a method and device for checking whether call data records in telecommunication systems have been created correctly and fully, specifically in mobile telephony networks, including the review of the data basis in the billing system, which is used to bill for the usage of the communications service.
Ragnar Huslende, in the printed publication ERICSSON Review, Vol. 72, No. 1, 1995, Stockholm, SE, pages 13-21, has described a way of measuring quality in public telecommunication networks. It is proposed that a number of review units be arranged in the telecommunication networks, which act like normal subscriber units and communicate with each other automatically via the network. During the communications connection, quality parameters, e.g., signal/noise distance are measured and routed to a central station where they are analyzed.
A similar method has also become known from the magazine TEC, Das technische Magazin von Ascom, 3/95, Bern, CH, pages 30-34, in an article by Heinz Lxc3xcthi. The article also proposes that communications connections, specifically voice connections, be established in a communications network via automated review stations, and that the respective voice quality of the review connections be analyzed and evaluated. The evaluation of the voice quality takes place with the use of neural diagnosis technology.
The present invention relates less to the review of the voice quality of a communications connection but rather to reviewing sets of communications data. Call data records are generated, saved and used to prepare the billing files in every telecommunication network. In digital mobile telephony networks, for example, these call data records are generated and saved in the mobile switching centers (MSC) and forwarded to a billing center, where the billing is handled jointly for all mobile telephony subscribers.
The creation of the call data records at the switching centers is purely software-driven and controlled via corresponding software parameters. Errors in the software and/or hardware and/or incorrectly adjusted software parameters can lead to malfunctions in the creation of the call data records, with the result that incomplete or defective call data records are created, or no call data records are created at all. If errors occur, they are usually identified only very late because the review of the call data records for correctness has so far been possible only in the form of spot checks, only for portions of the telecommunication network, and with a great deal of manual work.
It is in the interest of the customer and the operating company that the call data records are created correctly and that a correct billing takes place.
It is, therefore, the object of the invention to propose a method and device for checking whether call data records in a telecommunication system, or intercommunicatively in a plurality of telecommunication systems, have been created correctly and fully, whereby the accurate creation of call data records is reviewed permanently and automatically.
This object is met with a method according to the technical teaching of claim 1 and a device according to claim 23.
It is the principal feature of the invention that communications connections, which are oriented at the customer behavior or predefined by the operating company, are performed in the telecommunication network which is being reviewed by means of an automatic review system, in such a way that the communication parameters are recorded independently from each other and independently from the network, both at the calling station and at the called station. The call data records and billing data that are recorded by the telecommunication network itself are subsequently verified based on the reference data recorded by the review system. The special feature is that the reference data required for the verification are created by the system itself. These reference data are 100% qualitatively verified pairs of real call data records. The review encompasses all billing-relevant parameters, which are, among others:
Date,
Start time/end time of the call,
Duration of the call,
Location of the call, origin of the call,
Call destination, destination telephone number,
Utilized telecommunication service.
The review of the telecommunication network is performed during active operation, i.e., checking whether call data records are created correctly takes place under operating conditions. All elements of the telecommunication network are included, from the customer interface, the telecommunication end unit to the data basis in the telecommunication system""s billing system, which (for billing purposes) contains all billing-relevant call data records. It is also possible to check individual segments of the telecommunication network. The method is intended to provide the following functions:
Verification of telecommunication connections
The review system can be used to verify that a corresponding telecommunication connection did exist. The connection parameters are recorded both at the calling party and at the caller""s, and a check is performed whether a corresponding call data record for this connection was recorded in the telecommunication network itself. Both, end-to-end communications connections (customer interface to customer interface) as well as connections between any partial segments of the communications system (customer interface to operating company interface, or operating company interface to operating company interface) are reviewed.
Verification of call data records
The call data records that are created by the review system, in the following also referred to as reference data records, are compared to the call data records created by the telecommunication network.
Verification of the usability of the telecommunication connection
A determination is made, via the review system, to which extent a telecommunication connection was usable. During the review connection, review information is transmitted from both, the calling party and the called party to the respective opposite station. The review system determines the utilization of the telecommunication connection based on the received review information.
The advantage of the system according to the invention lies in the fact that a review of the call data records can now be performed automatically and permanently. The review can extend across one or multiple telecommunication networks.
It is furthermore possible to perform a cause-oriented error analysis for defective call data records based on the recorded network signaling data.
The method and device are explained in detail below, based on the example of a mobile telephony network. The method essentially comprises 5 process areas:
1. Creation of the customer-behavior oriented or operating-company oriented review scenarios for the call data records,
2. Generation of reference data records,
3. Generation of call data records by the telecommunication system,
4. Review of the telecommunication system""s call data records based on the reference data records, and review of the usability of the telecommunication connection,
5. Adaptation of the customer-behavior oriented or operating-company oriented call data record review scenarios, based on the indications of errors and error/cause analysis of the defective call data records.
1. Creation of customer-behavior oriented or operating-company oriented review scenarios for the call data records:
In order for the review of the call data records of the mobile telephony network to cover, to the fullest extent possible, the scope of services as they are also used by customers, a review scenario must be created that resembles the customer behavior. A statistically representative, anonymized customer call data record profile of, e.g., 10,000 data records is, therefore, generated from all customer-generated call data records of the active mobile telephony network, both with and without billing relevance. From these 10,000 data records, the review scenarios for the call data records are generated according to the following method:
The 10,000 data records are sorted in chronological order.
A review file (start time t1, end time tend) is defined. In the customer call data record profile, a search is performed for a data record with this predefined start time t1, e.g., Tuesday, 8:00 A.M. The parameters of this call data record (e.g., start of call, duration of call, communications service, call destination area, call origin area) are incorporated into the review file as data record 1.
The call duration t of data record 1, the system time tsystem, and t1 are used to determine the start time t2 of the second data record.
In the customer call data record profile, a search is now performed for a data record with the start time t2.
The parameters of the data record selected in this manner are in turn incorporated into the review file as data record 2. This is repeated until the desired review package has been created, or until the pre-defined end time tend has been reached.
With this method, a customer-behavior oriented review profile is created, which quasi corresponds to a cumulated xe2x80x9crealxe2x80x9d customer behavior. Since a review profile of this type can be permanently recreated, e.g., on a daily or weekly basis, changes in the customer behavior are directly reflected in the review profile because the customer call data record profile is always based on real call data records. In addition to the review package with customer-behavior oriented call data records, review packages can also be created with operating-company oriented call data records. With the operating-company oriented call data records, the call parameters are freely determined by the operating company. The review packages may also be created as mixed packages, from customer-behavior oriented and operating-company oriented call data records.
2. Creation of reference data records
To be able to make a statement regarding the quality of the complete communication data chain and billing-relevant production chain of a telecommunication network/system, the call data records created in the telecommunication system must be checked for their completeness and accuracy. Telephone calls made by customers cannot be used for this purpose. This is prohibited, on one hand, by data privacy regulations, and other the other handxe2x80x94which is a significant inaccuracy factor in the review of the qualityxe2x80x94no original data are available, such as what the customer really entered at his end unit, and when, how long, where to, etc.
To be able to conclusively evaluate the billing data at the end of the production chain, reference data records are created. This is done as follows:
From a system-internal sending station, connections to a system-internal answering station are established automatically via the telecommunication network being reviewed according to the review scenario defined and firmly established under Section 1 above, and terminated after specific call durations, which are defined in the review file. During the connection, review information is exchanged between the sending station and the answering station, and receipt of this information is rated and logged by both stations.
Both the sending station and the answering station can be operated as a stationary or mobile station.
At both stations, the sending station and the answering station, call data records are created and saved independently from each other, based on the actual connection parameters. Furthermore, the signaling data (e.g., Layer 2 and Layer 3) that are exchanged via the telecommunication system are logged in log files at the sending station and the answering station, respectively. These signaling data, as well as the review results from the exchange of the review information, which are also recorded in log files, are called up by the management system as needed (in the case of an error/cause analysis). A summary of the review results from each individual connection is incorporated into the call data record by both the sending station and the answering station as a quality parameter. The call data records are subsequently transmitted to a central management system, matched and compared to one another. Only call data records whose communication parameters are 100% identical are later used as reference data records for the verification of the call data records generated by the network. The defective data records are saved in files and routed to a cause-oriented automated or manual error analysis. With this method, reference data records are created for the review of the communication data from the telecommunication system, which are based on actual telephone connections, which are 100% complete and accurate, and whose call parameters are known conclusively.
3. Generation of call data records by the telecommunication system
From the sending station, connections are established to the answering station via the mobile telephony network. The network-internal call data records created at the switching centers (MSC) are transmitted to the central billing center (Data Post-Processing System, DPPS), where the call data records are available in a defined format for further transmitting to the management system.
4. Review of the telecommunication system""s call data records based on the reference data records, and review of the usability of the telecommunication connection:
The review of the telecommunication system""s call data records based on the reference data records takes place at the management system. For this purpose the call data records from the billing center are transmitted to the management system, where they are matched to the reference data record pairs (see section 2 xe2x80x9cCreation of reference data recordsxe2x80x9d) that are available at the management system, and compared to same to determine whether their communication parameters are identical. If the call data records do not match the reference data record pairs, they are saved in files, which are routed to an automatic and manual error analysis. In the automatic error analysis, the data records are split into error groups with the same error patterns and saved in error collectors. In a second step, the data records from individual error collectors are subjected to a manual error analysis.
5. Adaptation of the customer-behavior oriented or operating-company oriented call data record review scenarios based on the error indicators and error/cause analysis of the defective call data records.
The review scenarios for the telecommunication system""s call data records are supplemented or modified based on the data records saved in the error collectors. Review files are now created in a concentrated effort, whose parameters correspond to the job files that have led to the errors found during the review of the telecommunication network""s call data records. This specifically increases the likelihood that additional indicators for error checking and correction will become apparent.
For the error/cause analysis and recognition, the defective call data records and the corresponding signaling and connection data logged by the sending/answering stations and the mobile telephony devices, along with the logged results from the review information exchange between the stations, are routed to the management system where they are analyzed.